Conventional network management systems are comprised of network elements such as switches and transmission equipment. Network elements produce network event records such as report alarms responsive to the occurrence of network events. The term "network events", as used herein, refers to any event that may cause failure of network elements such as faulty transmission equipment, spliced cabling, switch abnormalities and the like. Network management systems are used to monitor communications networks and report alarms and other network events to users or system maintenance personnel.
Recent developments in network management systems enable networks to correlate many different network event records, for the purpose of showing users the correspondence between individual network events and individual network event records. Thus, users can track the effects of a given network event by analyzing the network event records produced responsive to the given network event. This is valuable because a single transmission outage, for example, can result in thousands of network event records being generated.
The present assignee has developed an international network management system, referred to as the International Community Information System (ICIS), that receives numerous network event records from switches and transmission network elements. Typical network event records include trunk alarms that report on the performance of a switch trunk. These network records are not related to any particular call or service. ICIS identifies and correlates switch alarms with transmission alarms, and presents information to the user indicative of the switch event records and transmission network event records that are related to a given network event. This method of network management identifies the network event records that are generated as a result of a given network event.
Typical communications networks support a variety of telephone services. Exemplary services include Inbound, Outbound and Outbound Transit. A limitation of prior art methods of network management is that they do not provide the user with an assessment of how telephone services are impacted by network events, including which services are impacted. This determination must be performed with manual analysis. In fact, many prior art systems are incapable of assessing service impact as a result of network events. This is because when a particular route fails, perhaps due to a fiber cut, calls are automatically switched to another route. This call switching is in accordance with normal network operations, and will go largely undetected as a problem. However, a particular service could be impacted by such an operation.
In addition, calls for a particular service can traverse several different routes. If there is a problem with a particular service, its impact would also traverse several different routes. Since prior art systems rely on the correlation of reported network events, said correlation based on network topology, they would not be able to correlate the different instances of a service problem, since service problems are frequently not tied to network topology.
Another limitation of prior art methods and systems of network management is that they only detect and report problems that result from switching and transmission hardware failures. Often, a minor software fault, such as an error in a call routing translation database, can result in many blocked calls. Since such a problem would not cause the generation of network equipment alarms, it would go undetected by prior art network management systems.